Electric switch.



I. G. DUNFEE.

ELECTRIC SWITCH.

APPLICATION FILED MAR. 2, 191g.

Patented Oct 29', 1912.

WITNE5SE5= 7 INVENTQR' ewM-iw A4 4 pairs er 1; PAT FKQO JOHN C. DUNFEE, OF CLEVELAND, OHIO, ASSIGNOR TO THE VAN DORN 82; DU'TTON COMPANY, OF CLEVELAND, OHIO, A CORPORATION OF OHIO.

ELECTRIC SWITCH.

Specification of Letters Patent.

Application filed March 2, 1912. Serial No. 681,021.

Patented Oct. me.

To all whom it may concern: I

Be it known that I, JOHN C. DUNFEE, a citizen of the'United States, and a resident of Cleveland, county of Cuyahoga, and State of Ohio, have invented a new and useful Improvement in' Electric Switches, of which the following is a specification, the principle of the invention being herein explained and the bestmode in which I have contemplated applying that principle, so as to distinguish it from the other inventions.

'My invention relates to electric switches and its general object is the provision of a switch which maybe conveniently operated by manipulation of a controlling member and which will be operated to break the circuit upon release of the controlling member.

The switch forming the subject of the present invention constitutes in general an improvement of the switch described and claimed in the co-pending application of Franklin Schneider, Serial No. 608,381, filed February 13, 1911.

To the accomplishment of these and related ends, said invention, then, consists of the means hereinafter fully described and particularly pointed out in the claims.

The annexed drawing and the following description set forth in detail certain mechanism embodying the invention, such dis closed means constituting, however, but one of various mechanical forms in which the form binding principle of the invention may be used.

In said annexed drawing: Figure 1 is an elevation of the switch, partly in section, the parts being shown in on position; F ig, 2 is a view similar to that of Fig. 1,'with the parts shown in off position; Fig. 3-

is a rear elevation taken when the parts are 111 on position; Fig. 4 1s a section on the line AA in Fig. 2; Fig. 5 is a section on the line B-B in Fig. 1, with certain parts shown in elevation.

My improved switch mechanism may be conveniently mounted, as shown in the drawing, within a casing 1 in which is rigidly secured a base 2 of insulating material upon which the permanent contacts are mounted. These contacts comprise preferably two spaced disks 3 of conducting mate rial which constitute preferably the head of bolts 5 which extend through the base 2 and posts on the rear side of the base, to which may be securedthe wires 6 of a circuit to be controlled. Disks 40f.

carbon are embedded in the base 2 so that they lie flush with the face of the base 2, and

the disks 4 are recessed so that the disks 3 may partly overlap the disks 4, the disks 3 is supported a piecell pressed toward the base 2 by springs 12, this piece being adapted in one rotative position of the frame to bridge the contacts 3.

reciprocable transversely of. the frames axis'of rotation, the catch 13 being formed near its center with a bent-up portion 14 adjacent which lie the cams'8 and 9 on the spindle 7.- A coil spring 15 is secured at its inner end to the spindle 7 and at its outer end to a post 16 provided on the frame 10. The frame further is provided with a pin 17. A spring118 tends to hold the catch 13 in its outer position, in which position it engages one or. the other of the diametrically opposite lugs 19 adjacent the contacts, or one or the other diametrically opposite- A catch 13 is sup-' ported on the front of the frame 10 and is lugs 20 which are thicker than the lugs 19.

On the rear of the spindle 7 is secured a ratchet wheel 21 provided at opposite points,

with teeth and having a smooth circumferential surface between the teeth; a springpressed pawl 22 bears against the ratchet wheel 21.

The operation of the switch is as follows:

Assume the catch to be in engagement with the right handllug 20 in Fig. 2, in which wise, and that, in the off position of the switch, such rotation is prevented by the the pin 17 with the cam 8. spindle and frame, with its contact piece, could be rotated counter clock-wise together, and the carelessness of the operator might result in such backward engagement of Consequently the pawl 22 will engage one of the teeth when the switch is in oil position. If the spin dle be rotated clock-wise from the position illustrated in Fig. 2, the cam 9 will withdraw the catch to a certain extent but not suiticiently to disengage it from the lug 20; after the cam 9 has passed out of contact .with the catch the spring 18 draws the catch into outer position again. The cam 9 is short enough to freely pass the pin 17 on further rotation of the spindle, but upon such further rotation the longer cam 8 completely withdraws the catch from lug 20. As soon as the catch is disengaged from the lug, the coil spring snaps the frame around relatively to the spindle one-quarter of a revolution, for as soon as the catch is freed from the cam 8 by its partial revolution, it flies out again and will engage the succeeding lug 19. In this position the circuit is complete, this position of the parts being illustrated in Fig. 1, although the catch is shown in engagement with the upper lug 19 instead of with the one succeeding the lug 20, with which the catch is engaged in Fig. 2. If. from the position shown in Fig. 1, the spin dle be further rotatedclock-wise, the long cam 8 will withdraw the catch from engagement with the lug 19 and the frame will fly around until the circuit is broken and the catch engages the succeeding lug 20. If, however, instead of being further rotated clock-wise when the catch is in engagement with the lug 19, the spindle he released, the tension of the coil spring will cause a rotation of the spindle in a counter clock-wise direction until the-cam 8 engages pin 17, and during this counter clock-wise movementof the spindle the cam 9 contacts with the catch 10 and withdraws it to such an extent that it will disengage itself from the narrow lug 19 and the frame will fiy 'tate in either direction.

,forward to ca position with the catch If the engaging the succeeding lug 20. ratchet wheel 21 be used, it will be so proportioned that when the'switch is in on 7 position the pawl 22 will not be in engagement with any of the teeth but'will bear on the smooth circumference between the teeth,

and therefore the spindle will be free to ro- "The switch may be conveniently used with an electric drill, for instance, so that by continued rotation ofthe handle of the drill,

which may be connected with the spindle, the operator may alternately throw the switch on and off without removing his hand-from the handle of the tool, and each time that the handle is operated the spring is thereby coiled for the next operation. If, however, when the switch is in on position, the operator releases the handle either from carelessness or from accident, the spindle will rotate counter clock wisc and the switch will automatically be thrown to ofl'position and danger will beg averted.

Other'modes of applying the principle of my invention may be employed instead of stated means be employed.

I therefore particularly point out and distinctly claim as my invention 1. In a deviceof the characterdescribed,

the combination of two contacts; a movable piece adapted in a first position to bridge break contact with said contacts; tension means for moving said piece; a catch for restraining such mo 'v'ement; and means adapted to render said tension'means' oper ative, said means being adapted, on move- 85. said contacts and in a second POSltlOIl to ment in one direction, to release said catch when said piece is in second position, and being adapted, on movement in either direction, to release said catch when said piece is in first position.

- 9.. In a device of the character described,

the combination of two contacts; a rotatable piece adapted in successive positions to al-' ternately makeand break contact with said contacts; tension means for rotating said piece; a catch for restraining such movement; and a spindle adapted to render such tension means operative, said spindle being adapted on rotation in one direction, to trip said catch when said piece is in 01? position, and being adapted, on rotation in.

either direction, to trip said catch when the piece is in on position.

3. In a device of the character described,

the combination of two contacts; a rotatable piece adapted in successive positions to alternately make and break contact with said contacts; a catch for restraining rotation of said piece; a rotatable spindle; tension means connecting said piece and said spindle; and means for tripping said catch, said means being operable by rotation ofthe spindle against said tension means when the piece is in ofl? position, and being operable by rotation of the spindle in either dlrection when the piece is in on position.

4. In a device of the character described, the combination of two contacts; a rotatable piece adapted in successive positions to alternately make and break contact with said contacts; a catch for restraining rotation of said piece; a rotatable spindle; tension 'means connecting said piece and said spin- 7 5 the one explained, change being made as regards the mechanism herein disclosed, provided the means stated by any of the following claims or the equivalent of such said catch when the piece is in either position; and a second cam on the spindle adapted to trip the catch only when the piece-is in on position, said cams being operative on rotation of the spindle in opposite directions.

5. In'a device of the character described, the combination of two contacts; a rotatable piece adapted in successive positions to alternately make and break contact with said contacts; a catch for restraining rotation of said piece; a rotatable spindle; a spring connecting said piece and spindle and tending to rotate them in opposite directions; a cam on said spindle operative on rotation of the spindle against tension to trip said catch when the piece is in either position; and a second cam on the spindle operative on rotation of the spindle by tension to trip said a catch only whensaid piece 1s in on position.

6. In a device of the character described, the combination of two contacts; a rotatable piece adapted in successive positions to alternately make and break contact with said contacts; a catch for restraining rotation of said piece; stops engaging said' catch at successivepositions of said piece, the stop at the off position of said piece being wider than the stop at the on position; a

' rotatable spindle; a spring connecting said piece and spindle and tending to rotate them in opposite directions; a cam on said spindle operative on rotation of the spindle against tension, said cam being of a length "tension, said adapted to disengage said catch from either of said stops; and a second cam on the spindle operative on rotation of the spindle by tension, said second cam being of a length adapted to disengage said catch from only the narrower of said stops.

,7. In a device of the character described, the combination of two contacts; a rotatable piece adapted in successive positions to alternately. make and break contact with said contacts; a catch for restraining rotation of said piece; stops engaging said catch at successive positions of said piece, the stop at the off position of said piece being wider than-the stop at the on position; a rotatable spindle; a spring connecting said piece and spindle and tending to rotate them in opposite directions; a cam on said spindle operative-on rotation of the spindle against cam being of a length adapted to disengage said catch from either of said stops; a second cam on the spindle operative on rotation of the spindle by tension, said second cam being of a length adapted to disengage said catch from only the narrower of said stops; and apin adapted to engage said first cam to limit rotation of said spindle by tension.

Signed'by me this 27th day of February ROBERT H, SEE, JNo. F. OBERLIN.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington,'D. G. 

